Under circumstances such as underwater imaging, selective damping of part of the color spectrum by the medium between objects and the camera or the objects and a light source can distort the relation between colors of the objects in the image. At depths of around 50 meters, little or nothing is left of the incoming blue light component. The problem of color selective damping can also occur in other circumstances. Similar problems may occur with images of a scene lighted by a colored light source.
Various standard color correction methods are available for correcting such images. For example, the average grey correction method applies different correction factors to different color channels such that the average of the color pixel values over the image has zero color saturation. As an alternative, the maximum white correction method uses correction factors that result in zero color saturation of the pixels with the highest overall intensity.
However, such techniques do not give satisfactory results if one or more color channels are strongly damped or selectively lighted. In this case, the resulting correction factor for such a channel can become very large and inaccurate, in which case the corrected value may show large errors. Moreover, in underwater imaging, the relative strength of the incoming color components can change with depth so that a method of correction that works well in one depth range may not work well in other depth ranges.